Cellulose polymers such as hydroxypropyl methylcellulose have long been recognized in the art as being suitable for the aqueous film coating of pharmaceutical tablets and the like.
While it is normally possible to produce excellent film coatings with such cellulosic materials, difficulties can sometimes arise with respect to the ability of the resultant film coatings to adhere satisfactorily to the surface to which they are applied. This is especially true when considering tablet substrates such as waxy matrix sustained release products and multivitamin products (with which the phenomenon of "bridging" of the coating across debossed legends can be a substantial problem).
It is also desirable to be able to produce film coatings for food and confectionery products which are able to replace the currently used sugar coatings, in order to meet the requirements for low calorie, noncariogenic (that is, not harmful to teeth) coatings for such products.
While cellulosic polymers can meet these requirements, they tend to produce coatings that have undesirable taste and mouth-feel (that is, they are somewhat bitter and slimy in texture; both undesirable features especially for confectionery products).